Index: llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp =================================================================== --- llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp +++ llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp @@ -1481,10 +1481,6 @@ if (LSRange.size() == 0) return false; - // If this range is neither open ended nor a constant, then it is not a - // candidate for being validThroughout. - if (RangeEnd && !DbgValue->getOperand(0).isImm()) - return false; // Determine if the DBG_VALUE is valid at the beginning of its lexical block. const MachineInstr *LScopeBegin = LSRange.front().first; @@ -1526,7 +1522,28 @@ if (DbgValue->getOperand(0).isImm() && MBB->pred_empty()) return true; - return false; + // Now check for situations where an "open-ended" DBG_VALUE isn't enough to + // determine eligibility for a single location, e.g. nested scopes, inlined + // functions. + // FIXME: For now we just handle a simple (but common) case where the scope + // is contained in MBB. We could be smarter here. + // + // At this point we know that our scope ends in MBB. So, if RangeEnd exists + // outside of the block we can ignore it; the location is just leaking outside + // its scope. + assert(LScopeEnd->getParent() == MBB && "Scope ends outside MBB"); + if (RangeEnd->getParent() != DbgValue->getParent()) + return true; + + // The location range and variable's enclosing scope are both contained within + // MBB, test if location terminates before end of scope. + for (auto I = RangeEnd->getIterator(); I != MBB->end(); ++I) + if (&*I == LScopeEnd) + return false; + + // There's a single location which starts at the scope start, and ends at or + // after the scope end. + return true; } /// Build the location list for all DBG_VALUEs in the function that Index: llvm/test/DebugInfo/X86/single-location-inlined-param.mir =================================================================== --- /dev/null +++ llvm/test/DebugInfo/X86/single-location-inlined-param.mir @@ -0,0 +1,114 @@ +# RUN: llc -start-after=livedebugvalues --filetype=obj %s -o - \ +# RUN: | llvm-dwarfdump -v -name=param - | FileCheck %s +# +# Generated with opt -sroa -inline, llc -stop-after=livedebugvalues, with some +# metadata removed by hand. +# +# int glob; +# __attribute__((always_inline)) +# static void inline_me(int param) { +# { +# int local = param; +# glob = local; +# } +# } +# int fun(int number) { +# inline_me(number); +# if (number) +# return 0; +# return 1; +# } +# +# The inlined parameter 'param' is available for the entirety of its enclosing +# scope. We expect to see a single location entry despite the fact that the +# final instruction in that scope belongs to a dominated scope. +# +# Except for 'param', all DILocalVariable metadata has been removed. +# +# Ignore first entry (abstract), we want to look at the concrete instance. +# CHECK: DW_TAG_formal_parameter [ +# CHECK: DW_TAG_formal_parameter [ +# CHECK-NEXT: DW_AT_location [DW_FORM_exprloc] (DW_OP_reg5 RDI) +# CHECK-NEXT: DW_AT_abstract_origin {{.*}} "param" + +--- | + target triple = "x86_64-unknown-linux-gnu" + + @glob = dso_local global i32 0, align 4, !dbg !0 + declare void @llvm.dbg.declare(metadata, metadata, metadata) + declare void @llvm.dbg.value(metadata, metadata, metadata) + define dso_local i32 @fun(i32 %number) !dbg !11 { + entry: + call void @llvm.dbg.value(metadata i32 %number, metadata !17, metadata !DIExpression()), !dbg !24 + store i32 %number, i32* @glob, align 4, !dbg !27 + %tobool = icmp ne i32 %number, 0, !dbg !32 + br i1 %tobool, label %return, label %if.end, !dbg !34 + + if.end: ; preds = %entry + br label %return, !dbg !35 + + return: ; preds = %entry, %if.end + %retval.0 = phi i32 [ 1, %if.end ], [ 0, %entry ], !dbg !16 + ret i32 %retval.0, !dbg !36 + } + + !llvm.dbg.cu = !{!2} + !llvm.module.flags = !{!7, !8, !9} + !llvm.ident = !{!10} + + !0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression()) + !1 = distinct !DIGlobalVariable(name: "glob", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true) + !2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 11.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, splitDebugInlining: false, nameTableKind: None) + !3 = !DIFile(filename: "test.c", directory: "/") + !4 = !{} + !5 = !{!0} + !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) + !7 = !{i32 7, !"Dwarf Version", i32 4} + !8 = !{i32 2, !"Debug Info Version", i32 3} + !9 = !{i32 1, !"wchar_size", i32 4} + !10 = !{!"clang version 11.0.0"} + !11 = distinct !DISubprogram(name: "fun", scope: !3, file: !3, line: 9, type: !12, scopeLine: 9, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !14) + !12 = !DISubroutineType(types: !13) + !13 = !{!6, !6} + !14 = !{} + !16 = !DILocation(line: 0, scope: !11) + !17 = !DILocalVariable(name: "param", arg: 1, scope: !18, file: !3, line: 3, type: !6) + !18 = distinct !DISubprogram(name: "inline_me", scope: !3, file: !3, line: 3, type: !19, scopeLine: 3, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !21) + !19 = !DISubroutineType(types: !20) + !20 = !{null, !6} + !21 = !{!17} + !23 = distinct !DILexicalBlock(scope: !18, file: !3, line: 4, column: 3) + !24 = !DILocation(line: 0, scope: !18, inlinedAt: !25) + !25 = distinct !DILocation(line: 10, column: 3, scope: !11) + !26 = !DILocation(line: 0, scope: !23, inlinedAt: !25) + !27 = !DILocation(line: 6, column: 10, scope: !23, inlinedAt: !25) + !32 = !DILocation(line: 11, column: 7, scope: !33) + !33 = distinct !DILexicalBlock(scope: !11, file: !3, line: 11, column: 7) + !34 = !DILocation(line: 11, column: 7, scope: !11) + !35 = !DILocation(line: 13, column: 3, scope: !11) + !36 = !DILocation(line: 14, column: 1, scope: !11) + +... +--- +name: fun +body: | + bb.0.entry: + successors: %bb.2(0x50000000), %bb.1(0x30000000) + liveins: $edi + + DBG_VALUE $edi, $noreg, !17, !DIExpression(), debug-location !24 + MOV32mr $rip, 1, $noreg, @glob, $noreg, renamable $edi, debug-location !27 :: (store 4 into @glob) + renamable $eax = XOR32rr undef $eax, undef $eax, implicit-def dead $eflags + TEST32rr killed renamable $edi, renamable $edi, implicit-def $eflags, debug-location !32 + JCC_1 %bb.1, 4, implicit $eflags, debug-location !34 + + bb.2.return: + liveins: $eax + + RETQ $eax, debug-location !36 + + bb.1.if.end: + renamable $eax = MOV32ri 1 + RETQ $eax, debug-location !36 + +... Index: llvm/test/DebugInfo/X86/single-location-interrupted-scope.mir =================================================================== --- /dev/null +++ llvm/test/DebugInfo/X86/single-location-interrupted-scope.mir @@ -0,0 +1,182 @@ +# RUN: llc -start-after=livedebugvalues --filetype=obj %s -o - \ +# RUN: | llvm-dwarfdump -v -name=parama - | FileCheck %s +# +# Generated with -O2, llc -stop-after=livedebugvalues, with IR modified from +# this source: +# +# int globa, globb; +# void ext(); +# static void set(int parama, int paramb) { +# globa = parama; +# globb = paramb; +# } +# void funone(int one, int two) { +# two = two + one; +# // 'two = ...' sunk between the inlined assignments to globa and globa. +# set(one, two); +# if (two > 0) +# return ext(); +# } +# void funtwo(int one, int two) { +# two = one + two; +# // 'two = ...' sunk between the inlined assignments to globa and globa, +# // and rdi is clobbered by the sunk 'two = ...'. +# set(one, two); +# if (one < two) +# return ext(); +# } +# +# Check that the 'parama' is available for the entire inlined scope in funone, +# and that it is unavailable in the second DW_AT_ranges segment of the inlined +# scope in funtwo. In both cases the inlined scope 'set' is intrerrupted by an +# instruction from the calling function. +# +# Except for 'parama', all DILocalVariable metadata has been removed. +# +# Ignore first entry (abstract), we want to look at the concrete instances. +# CHECK: DW_TAG_formal_parameter [ +# CHECK: DW_TAG_formal_parameter [ +# CHECK-NEXT: DW_AT_location [DW_FORM_exprloc] (DW_OP_reg5 RDI) +# CHECK-NEXT: DW_AT_abstract_origin {{.*}} "parama" +# CHECK: DW_TAG_formal_parameter [ +# CHECK-NEXT: DW_AT_location [DW_FORM_sec_offset] +# CHECK-NEXT: [0x{{[0-9a-b]+}}, 0x{{[0-9a-b]+}}) +# CHECK-NEXT: DW_AT_abstract_origin {{.*}} "parama" + +--- | + target triple = "x86_64-unknown-linux-gnu" + + @globa = dso_local local_unnamed_addr global i32 0, align 4, !dbg !0 + @globb = dso_local local_unnamed_addr global i32 0, align 4, !dbg !10 + + declare !dbg !6 dso_local void @ext(...) local_unnamed_addr + declare void @llvm.dbg.value(metadata, metadata, metadata) + + define dso_local void @funone(i32 %one, i32 %two) local_unnamed_addr !dbg !17 { + entry: + call void @llvm.dbg.value(metadata i32 %one, metadata !20, metadata !DIExpression()), !dbg !23 + store i32 %one, i32* @globa, align 4, !dbg !25 + %add = add nsw i32 %two, %one, !dbg !30 + store i32 %add, i32* @globb, align 4, !dbg !31 + %cmp = icmp sgt i32 %add, 0, !dbg !32 + br i1 %cmp, label %if.then, label %if.end, !dbg !34 + + if.then: ; preds = %entry + tail call void (...) @ext(), !dbg !35 + ret void, !dbg !36 + + if.end: ; preds = %entry + ret void, !dbg !36 + } + + define dso_local void @funtwo(i32 %one, i32 %two) local_unnamed_addr !dbg !37 { + entry: + call void @llvm.dbg.value(metadata i32 %one, metadata !20, metadata !DIExpression()), !dbg !41 + store i32 %one, i32* @globa, align 4, !dbg !43 + %add = add nsw i32 %two, %one, !dbg !44 + store i32 %add, i32* @globb, align 4, !dbg !45 + %cmp = icmp sgt i32 %two, 0, !dbg !46 + br i1 %cmp, label %if.then, label %if.end, !dbg !48 + + if.then: ; preds = %entry + tail call void (...) @ext(), !dbg !49 + ret void, !dbg !50 + + if.end: ; preds = %entry + ret void, !dbg !50 + } + + !llvm.dbg.cu = !{!2} + !llvm.module.flags = !{!13, !14, !15} + !llvm.ident = !{!16} + + !0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression()) + !1 = distinct !DIGlobalVariable(name: "globa", scope: !2, file: !3, line: 16, type: !12, isLocal: false, isDefinition: true) + !2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 11.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, retainedTypes: !5, globals: !9, splitDebugInlining: false, nameTableKind: None) + !3 = !DIFile(filename: "test.c", directory: "/") + !4 = !{} + !5 = !{!6} + !6 = !DISubprogram(name: "ext", scope: !3, file: !3, line: 17, type: !7, spFlags: DISPFlagOptimized, retainedNodes: !4) + !7 = !DISubroutineType(types: !8) + !8 = !{null, null} + !9 = !{!0, !10} + !10 = !DIGlobalVariableExpression(var: !11, expr: !DIExpression()) + !11 = distinct !DIGlobalVariable(name: "globb", scope: !2, file: !3, line: 16, type: !12, isLocal: false, isDefinition: true) + !12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) + !13 = !{i32 7, !"Dwarf Version", i32 4} + !14 = !{i32 2, !"Debug Info Version", i32 3} + !15 = !{i32 1, !"wchar_size", i32 4} + !16 = !{!"clang version 11.0.0"} + !17 = distinct !DISubprogram(name: "funone", scope: !3, file: !3, line: 22, type: !18, scopeLine: 22, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !4) + !18 = !DISubroutineType(types: !19) + !19 = !{null, !12, !12} + !20 = !DILocalVariable(name: "parama", arg: 1, scope: !21, file: !3, line: 18, type: !12) + !21 = distinct !DISubprogram(name: "set", scope: !3, file: !3, line: 18, type: !18, scopeLine: 18, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !22) + !22 = !{!20} + !23 = !DILocation(line: 0, scope: !21, inlinedAt: !24) + !24 = distinct !DILocation(line: 24, column: 3, scope: !17) + !25 = !DILocation(line: 19, column: 9, scope: !21, inlinedAt: !24) + !30 = !DILocation(line: 23, column: 13, scope: !17) + !31 = !DILocation(line: 20, column: 9, scope: !21, inlinedAt: !24) + !32 = !DILocation(line: 25, column: 11, scope: !33) + !33 = distinct !DILexicalBlock(scope: !17, file: !3, line: 25, column: 7) + !34 = !DILocation(line: 25, column: 7, scope: !17) + !35 = !DILocation(line: 26, column: 12, scope: !33) + !36 = !DILocation(line: 27, column: 1, scope: !17) + !37 = distinct !DISubprogram(name: "funtwo", scope: !3, file: !3, line: 28, type: !18, scopeLine: 28, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !38) + !38 = !{} + !41 = !DILocation(line: 0, scope: !21, inlinedAt: !42) + !42 = distinct !DILocation(line: 30, column: 3, scope: !37) + !43 = !DILocation(line: 19, column: 9, scope: !21, inlinedAt: !42) + !44 = !DILocation(line: 29, column: 13, scope: !37) + !45 = !DILocation(line: 20, column: 9, scope: !21, inlinedAt: !42) + !46 = !DILocation(line: 31, column: 11, scope: !47) + !47 = distinct !DILexicalBlock(scope: !37, file: !3, line: 31, column: 7) + !48 = !DILocation(line: 31, column: 7, scope: !37) + !49 = !DILocation(line: 32, column: 12, scope: !47) + !50 = !DILocation(line: 33, column: 1, scope: !37) + +... +--- +name: funone +body: | + bb.0.entry: + successors: %bb.2(0x50000000), %bb.1(0x30000000) + liveins: $edi, $esi + + DBG_VALUE $edi, $noreg, !20, !DIExpression(), debug-location !23 + MOV32mr $rip, 1, $noreg, @globa, $noreg, renamable $edi, debug-location !25 :: (store 4 into @globa) + renamable $esi = ADD32rr killed renamable $esi, killed renamable $edi, implicit-def $eflags, debug-location !32 + MOV32mr $rip, 1, $noreg, @globb, $noreg, killed renamable $esi, debug-location !31 :: (store 4 into @globb) + JCC_1 %bb.1, 14, implicit $eflags, debug-location !34 + + bb.2.if.then: + dead $eax = XOR32rr undef $eax, undef $eax, implicit-def dead $eflags, implicit-def $al, debug-location !35 + TAILJMPd64 @ext, csr_64, implicit $rsp, implicit $ssp, implicit $rsp, implicit $ssp, implicit killed $al, debug-location !35 + + bb.1.if.end: + RETQ debug-location !36 + +... +--- +name: funtwo +body: | + bb.0.entry: + successors: %bb.2(0x50000000), %bb.1(0x30000000) + liveins: $edi, $esi + + DBG_VALUE $edi, $noreg, !20, !DIExpression(), debug-location !41 + MOV32mr $rip, 1, $noreg, @globa, $noreg, renamable $edi, debug-location !43 :: (store 4 into @globa) + renamable $edi = nsw ADD32rr killed renamable $edi, renamable $esi, implicit-def dead $eflags, debug-location !44 + MOV32mr $rip, 1, $noreg, @globb, $noreg, killed renamable $edi, debug-location !45 :: (store 4 into @globb) + TEST32rr killed renamable $esi, renamable $esi, implicit-def $eflags, debug-location !46 + JCC_1 %bb.1, 14, implicit $eflags, debug-location !48 + + bb.2.if.then: + dead $eax = XOR32rr undef $eax, undef $eax, implicit-def dead $eflags, implicit-def $al, debug-location !49 + TAILJMPd64 @ext, csr_64, implicit $rsp, implicit $ssp, implicit $rsp, implicit $ssp, implicit killed $al, debug-location !49 + + bb.1.if.end: + RETQ debug-location !50 + +... Index: llvm/test/DebugInfo/X86/single-location.mir =================================================================== --- /dev/null +++ llvm/test/DebugInfo/X86/single-location.mir @@ -0,0 +1,82 @@ +# RUN: llc -start-after=livedebugvalues --filetype=obj %s -o - \ +# RUN: | llvm-dwarfdump -v - | FileCheck %s +# +# Generated at -O2, stopped after livedebugvalues, with some metadata removed +# by hand: +# int global; +# void ext(); +# void fun(int p) { +# { +# int local = p; +# global = local; +# } +# ext(); +# } +# +# The variable 'local' is available for the entirety of its enclosing scope so +# we expect to see a single location entry. +# +# Except for 'local', all DILocalVariable metadata has been removed. +# +# CHECK: DW_TAG_lexical_block [ +# CHECK: DW_TAG_variable +# CHECK-NEXT: DW_AT_location [DW_FORM_exprloc] (DW_OP_reg5 RDI) +# CHECK-NEXT: DW_AT_name {{.*}} = "local" + +--- | + target triple = "x86_64-unknown-linux-gnu" + @global = dso_local local_unnamed_addr global i32 0, align 4, !dbg !0 + define dso_local void @fun(i32 %p) local_unnamed_addr !dbg !15 { + entry: + call void @llvm.dbg.value(metadata i32 %p, metadata !20, metadata !DIExpression()), !dbg !23 + store i32 %p, i32* @global, align 4, !dbg !24 + tail call void (...) @ext(), !dbg !29 + ret void, !dbg !30 + } + + declare !dbg !6 dso_local void @ext(...) local_unnamed_addr + declare void @llvm.dbg.value(metadata, metadata, metadata) + + !llvm.dbg.cu = !{!2} + !llvm.module.flags = !{!11, !12, !13} + !llvm.ident = !{!14} + + !0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression()) + !1 = distinct !DIGlobalVariable(name: "global", scope: !2, file: !3, line: 1, type: !10, isLocal: false, isDefinition: true) + !2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 11.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, retainedTypes: !5, globals: !9, splitDebugInlining: false, nameTableKind: None) + !3 = !DIFile(filename: "test.c", directory: "/") + !4 = !{} + !5 = !{!6} + !6 = !DISubprogram(name: "ext", scope: !3, file: !3, line: 2, type: !7, spFlags: DISPFlagOptimized, retainedNodes: !4) + !7 = !DISubroutineType(types: !8) + !8 = !{null, null} + !9 = !{!0} + !10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) + !11 = !{i32 7, !"Dwarf Version", i32 4} + !12 = !{i32 2, !"Debug Info Version", i32 3} + !13 = !{i32 1, !"wchar_size", i32 4} + !14 = !{!"clang version 11.0.0"} + !15 = distinct !DISubprogram(name: "fun", scope: !3, file: !3, line: 3, type: !16, scopeLine: 3, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !18) + !16 = !DISubroutineType(types: !17) + !17 = !{null, !10} + !18 = !{!20} + !20 = !DILocalVariable(name: "local", scope: !21, file: !3, line: 5, type: !10) + !21 = distinct !DILexicalBlock(scope: !15, file: !3, line: 4, column: 3) + !22 = !DILocation(line: 0, scope: !15) + !23 = !DILocation(line: 0, scope: !21) + !24 = !DILocation(line: 6, column: 12, scope: !21) + !29 = !DILocation(line: 8, column: 3, scope: !15) + !30 = !DILocation(line: 9, column: 1, scope: !15) + +... +--- +name: fun +body: | + bb.0.entry: + liveins: $edi + + DBG_VALUE $edi, $noreg, !20, !DIExpression(), debug-location !23 + MOV32mr $rip, 1, $noreg, @global, $noreg, killed renamable $edi, debug-location !24 :: (store 4 into @global) + dead $eax = XOR32rr undef $eax, undef $eax, implicit-def dead $eflags, implicit-def $al, debug-location !29 + TAILJMPd64 @ext, csr_64, implicit $rsp, implicit $ssp, implicit $rsp, implicit $ssp, implicit killed $al, debug-location !29 +...